The present invention relates in general to a vehicle temperature sensing device that samples air from an interior passenger compartment to determine passenger compartment temperature. More particularly, the present invention relates to a device that purges air in a region surrounding a temperature sensor, in favor of passenger compartment air, the purging taking place before the vehicle's automatic temperature control system is activated.
Automatic temperature control ("ATC") systems are known to measure interior compartment temperature. The measured temperature is used by the ATC system to activate subsystems that will lower or raise compartment temperature to meet passenger expectations. Relevant subsystems of the ATC system include ventilation mode, recirculation door positions, blower speeds and refrigeration cycles.
Typically, a sensor or thermistor that measures interior passenger compartment temperature is located in a dashboard of the vehicle, a region of the vehicle that generally maintains a temperature different from that of the passenger compartment. Before passenger compartment temperature may be accurately measured, air in the immediate area of the sensor must be purged in favor of air pulled in from the passenger compartment.
With regard to conventional ATC systems, purging does not typically begin until after the ATC is activated, which occurs after the ignition system of the vehicle is activated. Until the air having a temperature that is dissimilar to that of the vehicle passenger compartment is purged from the area surrounding the sensor or thermistor located in the dashboard, precise implementation of ATC subsystems is impossible. The ATC system can only make gross assumptions regarding compartment air temperature.
Ventilation related systems are known that are activated when a key is inserted into a vehicle door, or the door is unlocked. Such systems, however, do not suggest or teach the importance of obtaining an accurate temperature measurement of interior compartment air by purging air of dissimilar temperature from the region of the temperature sensor before the system begins to make measurements.